Woe.  The noise of the 50 Ohm resistor is ~1 nV/rHz. The gain of your opamp is 100k/50 = 2000. So the output noise should be at least 2 uV/rHz.

Its better to diagnose the noise by not having the resistor there and/or to put the PD there. I have also added the LT1792 to the LISO SVN.